To think dh should butt out of ds' s gf choice?

[DPSN]

Have posted before about DH's reactions to DS' s choices re university and gf.
Relations between ds and rest of family are strained and he avoids spending time at home and only brings gf home if dh is not home.
DH doesn't approve of gf, ds senses this. DH thinks he can influence dc's choice of gf. I disagree.
DH wants to tell ds that his gf is not 'the one' in his I know what is best for you way. I think this is a mistake and would drive ds away further. Honestly, I hope she is not 'the one' but surely it is not my choice to make?!
DH thinks I am too tolerant and it is his duty to tell ds that his gf is a loser. She doesn't smoke, drink, do drugs or anything criminal, is just a bit dull if you ask me, has little ambition, no discernible hobbies or sparkle.
AIBU to let ds get on with his relationship as he sees fit? I am currently convinced that the answer is 'no', dh is convinced the answer is 'yes' and sees it as a parental duty to tell ds he has made a lousy choice - knowing that this would make strained relations even worse.
What do others think?

saying that somehow this opinion must be detectable even when not expressed openly is ridiculous.

It's certainly not impossible though. Even if you try to hide it, there may be lots of giveaways that you don't like someone, such as body language, less eye contact, a general tension

To infer it as what is actually happening as poster have done on this thread is pure invention.

I have been the girlfriend in a house where I was clearly not welcome.

I can TOTALLY understand why she may not have wanted to come out.

I've been the fiancée thrown out of my (now) MIL's house on Christmas Day. To his credit DH came with me. I then had to return to that house a few days later to have meals with the family who acted as if nothing had happened (other than ignoring me). It was horrible but I loved my DH and didn't want him to be forced to break with his family.

Years later I have provided MIL with her only grandson (which I'm sure she secretly hates me for) and am polite but never affectionate with her. She will get hers one day - revenge is a dish best eaten frozen!

Sorry it didn't go as planned. Having accepted the invitation, they should have honoured the commitment.

However, I would guess at cold feet and nerves here. Perhaps your DH has already said too much so both realise that the girlfriend is not truly welcome even though he may pretend otherwise at the meal table. They may have been worried that it would resemble the Spanish Inquisition.

In your shoes, I would tell your DS A(calmly) that you are definitely on his side and distancing yourself from his Dad's hot headedness and negativity, the cause was not helped by what happened last night because of the titanic efforts involved in bringing Dad round to a calmer way of thinking. In fact, they probably inadvertently reinforced your DH's negative opinions just when you had fought to create a chance, however tiny, of quietening him.

I think a more softly softly approach might be better. You meet your DS and his girlfriend in town for a coffee without DH in tow. Get to know her that way several times. Eventually it may work with DH present too because at least she would have begun to relax a bit with you by then, and he (DH) will have had time to reflect.